Grinding mill



April 6, 1943. WALLACE 2,316,632 GRINDING MILL 2 Sheets-Sheet 1 Filed March 19, 1942 v INVENTDH Jam! .1 WAL LACE A T T u RNEY April 6, 1943. WALLACE 2,316,032

GRINDING MILL File'd March 19, 1942 2 Sheets-Sheet 2 IHYENTCIH JOHN J WALL/m5 IATTDRNEY Patented Apr. 6, 1943 v UNITED STATES PATENT OFFICE I GRINDING MlLL 7 John J. Wallace, Gouvcrneur, N. Y. Application March 19, 1942, Serial no. 435,366

1 Claim. .(ci. 83-8) My invention relates to improvements in a grinding mill in which a revolving cylinder operates in conjunction with a pressure roller mounted in said cylinder. The objects of my improvement are, first, to provide a mill particularly adapted for grinding or pulverizing talc ore or the like which will grind the material more uniformly and rapidly than has been accomplished heretofore; second, to afford facilities for maintaining the material cool and uncontaminated by foreign material during the grinding and pulverizing operation whereby the product obtained will have a natural untarnished color; and, third, to produce a mill of this character which is efficient, relatively easy in operation and which is simple, durable and economical in construction. p

In carrying out the above mentioned objects, I have produced a mill comprising a drum or cylinder and a pressure roller which is mounted in the drum or cylinder. The cylinder is rotatably supported upon roller bearings and may be driven from any suitable source of power. The pressure roller is loosely mounted in the cylinder in en-- gagement with the lower inner side of said cylinder and is rotated by the cylinder through frictional contact therewith. This provides a grinding mill which may be operated at the required speed with a minimum amount of power. Furthermore, the adjacent contacting surfaces of the cylinder and pressure roller are covered with suitable brick conducive to long life and which provide hard, substantially smooth grinding surfaces that will not contaminate the material being ground. Furthermore, these hard smooth surfaces are such that the material being ground does not cling thereto with the result that the clogging of the cylinder and roller iseliminated and the grinding operation of these members is continuously maintained at maximum efliciency.

These and other objects pertaining to the specific construction and operation of my device will more fully appear from the following description taken in conjunction with the accompanying drawings, in which:

Figure 1 is a longitudinal vertical sectional view of a grinding mill embodying the various features of my invention, the section being taken substantially on the line l-l, Figure 2.

Figure 2 is a transverse vertical sectional view taken substantially in the plane of the line 2-2, Figure 1.

The grinding mill illustrated in the drawings comprises a supporting, frame 5 composed primarily of I-beams secured together in any suitable manner as by electric welding, riveting or the like. The frame comprises a base portion 6 havingjstandards 1 extending upwardly from opposite ends thereof, the standards ateach end of the base being connected to each other by cross beams 8. Positioned over the base ii between the end standards I is a hollowcylinder or drum In which is mounted upon two sets of roller hearings to rotate about a horizontal axis. Each set of bearings comprises a roller bearing l l and two roller bearings l2. These roller bearings are rotatably connected with the frame 5 by respective shafts l3 journaled in suitable bearings I4. The roller bearings H' are arranged directly below the cylinder in and are provided with peripheral grooves I l which receive therein raised track portions I6 of corresponding bearing rings l'l secured to the periphery'of the cylinder I0. Roller bearings ll thus not only support the cylinder but also maintain said cylinder against axial movement. The roller bearings I2 are arranged at either side of, the roller ll of the corresponding set and may be provided with plane surfaces contacting the corresponding ring ll, as illustrated inFigure 2. The cylinder l0 may be rotated by any suitable power means such as by a belt l9 connected with a motor (not shown) and trained around a pulley 20 secured to the cylinder in at one end thereof.

The pressure roller 22 mounted within the cylinder I0 is of less diameter than the interior of said cylinder and is in contact with the lower portion of the inner circumferential surface of the cylinder to be supportedthereby. While I have illustrated the pressure roller 22 as being hollow, it will be understood thatlthe roller may be formed solid or it may be filled with water or other suitable liquid in order to increase the weight thereof. As indicated in the drawings, theinner circumferential surface of the cylinder I0 and the outer peripheral surface of the pressure roller 22 are preferably covered with suitable material which provides a hard smooth surface that is. conducive to long life and that will not contaminate the material being ground. As ini dicated in the drawings, these members are covered with bricks 23 and composed preferably of porcelain or other similar material which provides an exceptionally hard surface that will not readily wear when pulverizing talc or similar material. The bricks 23 are secured to the inner circumferentialsurface of the cylinder Ill in a plurality of, in, this instance 4, sections 25, said sections being arranged 1 in circumferentially.

spaced relation to each other and separated by nally thereof. These channels or gutters extend into the bars from their mouths in a direction generally converse to the direction of rotation of the cylinder to adapt the channels to receive at least a portion of the material being ground.

therein and to carry the same upwardly to a po-- sition over the pressure roller 22 and then to de-" posit the material on said roller at the posterior side thereof so that portions of the material which have not been ground sufiiciently to be re-" moved from the cylinder are passed again be tween the pressure roller 22 and cylinder it.

The bricks 24 mounted on the roller 22 may be secured thereto in an-y suitable manner. As illustratedin Figure 2 of the drawings, the bricks are secured to the roller by means of cleats or bars 28 extending longitudinally of the roller and which may be secured thereto in uniform circumferential spaced relation to each other by rivets, bolts, or electric welding. The cleats 28 are dovetailed in cross section and are received in corresponding dovetailed recesses 29 provided in the longitudinal sides of the bricks 24. When assembling the bricks 24 with the roller 22, the bricks are moved longitudinally along the spaces between; adjacent cleats 28 and are maintained against longitudinalmovementwith respect to the roller after'being properly positioned thereon by suitable end plates 3t. These plates 30 are of segmental form and may be secured to the ends of the roller in any suitable manner, as by rivets The pressure roller 22 is loosely mounted in the cylinder in. to be rotated thereby and, therefore, is free to move laterally toward and from the inner circumferential surface of the cylinder during thegrinding operation. In order that the pressure roller may have only a limited axial movement with respect to the cylinder I5, I have provided suitable thrust members 33 and 34 which operatively connect the roller with the frame 5. These thrust members are constructed substantially alike and each comprises a gudgeon 35 which is connected with a corresponding end 35 of the pressure roller 22 substantially coaxially therewith. The gudgeons may be connected with the pressure roller by any suitable means such as by electric welding. These members 35 exe tend outwardly from the roller through suitable apertures 31 or 33' provided in the ends 31 and 3B of cylinder H1. The outer end of each gudgeon 35is provided with an outwardly extending circular flange 39 which is loosely received in a circular recess 40 provided in a head or bearing 4|, which is secured to the corresponding frame standards 1 by transversely disposed angle bars 42 as indicated in Figure 1; The opening 518' in the cylinder IE! is of greater diameter than the roller 22 so that said roller may be readily moved into or out of the cylinder. The aperture 3 1' in the opposite end of the cylinder I0 is of relatively small diameter, being only large enough to readily receive the flange 39 of a gudgeon 35 therethrough. If desired, the opening 31' 'may be partly closed by a cover plate 44 secured to the end:31 of the cylinder and which has an aperjacent gudgeon 35 therein and to permit the necessary lateral movement of said gudgeon produced by the roller 22 during the grinding operation.

The material to be ground is fed to the interior of the cylinder H1 by a worm conveyor 46 which extends horizontally through the cylinder. The ends of the conveyor housing 41 are secured to the corresponding cross beams 8 by suitable brackets 48, as indicated in the drawings. One end of the conveyor housing 41 is provided with a hopper 49 for feeding the material into the conveyor. The helix 50 of the conveyor is journaled in suitable bearings 5! secured to the cross beams 8 and may be driven in any suitable manner as by means of a pulley 52 and a belt (not shown) extending from said pulley to a suitable source of power. The conveyor it is preferably arranged in a plane over the pressure roller 22 at the posterior side of said roller and is provided with a longitudinal slot 55 in the bottom of the housing 41 through which the material being urged longitudinally through the housing passes to themterior of thecylinder i8. Any material which does not pass through the slot 54may be discharged from the conveyor through a'discharge tube 55. secured to the housing 41 at the end thereof opposite the hopper 49.

In order that the material being ground in the cylinder may be readily removed therefrom, 'I have provided a suction" or exhaust conduit 51 which extends through a suitable aperture 58 formed in the nearly closed end 31 of'the cylinder It]. This conduit 51 may be connected with a suitable suction fan (not shown). When the material in the cylinder ii] is ground or pulverized to the degree desired, the same is picked up ture 45 therethrough adapted to receive the ad by the air entering the cylinder ID at one end through the aperture 38, and is drawn out with said air at the opposite end of the. cylinder through conduit 51. This circulation of air through cylinder 10 is thus utilized to maintain the mill and material cool as well as to remove the ground material therefrom. Particles of the material which have not been ground suificiently to be carried out by the air current passing through the cylinder I 0 enter the channels or gutters 26 and are carried upwardly to a position over the roller 22 and then pass from the chan nels or gutters downwardly at the posterior side of the roller, where they are again subjected to the'grinding action of the roller.

Although the construction and operation of my grinding mill is relatively simple, I do not wish to be limited to the details of the device or to their arrangement as shown and described, as various changes may be made therein without departing from the spirit of the invention as set forth in the appended claim.

I claim: H

A grinding mill of the kind having a grinding cylinder rotative about a fixed horizontal axis, driving means for said cylinder, and a floating grinding roll of substantially less diameter than the internal diameter of said cylinder located within and extending longitudinally of the cylinder and movable by gravity into contact with the cylinder, characterized in that the cylinder of hard and wear resistant vitreous material,

and the grinding covering of the cylinder com: prising a plurality'of circumferentially spaced segmental portions each constructed of blocks of hard and wear resistant vitreous material and also comprising a plurality of spacing bars of hard and Wear resistant material each closing the gap between the adjacent ends of two of said segmental portions of the covering, each of which spacing bars has formed therein a channel which extends substantially throughout the length of the spacing bar and extends into the spacing bar from the grinding surface of the cylinder coveringin adirection generally converse to the direction of rotation of the cylinder to pick up material being ground at the lower part of the cylinder and discharge the picked up material upon the upper portion of the roll.

JOHN J. WALLACE. 

